Thursday, September 11, 2008

What is ANGIOGRAM / ANGIOPLASTY ?

  • What is an angiogram ?
  • Preparation for the angiogram
  • During the angiogram
  • After the angiogram
  • When do I know the angiogram result ?
  • What is an Angioplasty ?
  • During the angioplasty
  • After the angioplasty
  • What are the possible side effects/complications ?
  • Can I do anything to help myself ?
  • How effective is angioplasty ?

ANGIOGRAM

What is an angiogram ?

The picture below is an angiogram of the blood vessels around the hip joint. An angiogram is a special form of x-ray that permits the diagnosis of blockages (occlusions) or narrowings (stenosis) in the arteries of the body. During the test, a tube (catheter) is inserted into an artery at the groin. A special radio-opaque dye (contrast medium) is injected down the tube and x-ray pictures are taken as the solution passes along the blood vessels. The whole procedure usually lasts approximately one hour. The arteries take blood from the heart to supply oxygen to muscles and organs and the angiogram will tell your doctor if the supply of blood is being affected. The procedure is performed by a specialist interventional radiologist or a vascular surgeon.


Preparation for the angiogram

You will normally be admitted to the ward for a few hours beforehand to check out your general health and to prepare you for the angiogram. On the day of the test you may eat and drink as normal although this may vary between hospitals. If you take regular medications you should take your usual morning doses. The only exception to this might be if you are taking warfarin, in which case you should follow instructions provided for you. Frequently warfarin is stopped before an angiogram, but not always. If you have diabetes and inject insulin you should have your normal food and insulin dose, unless instructed not to. On arrival, you will be seen briefly by the doctor, the test will be explained to you and you will be asked to sign a consent form. This is to ensure you understand the test and its implications. Please tell the doctor if you have had any allergies or bad reactions to drugs or other tests. It would also be helpful to mention to the doctor if you have asthma, hay fever, diabetes, or any heart or kidney problems. Kidney problems can be particularly important.

This is because the dye used to outline the arteries can damage the kidneys if special precautions are not taken. If you have any worries or queries at this stage don't be afraid to ask. The staff will want you to be as relaxed as possible for the test and will not mind answering your queries. You will be asked to put on a hospital gown. The test will take place in the x-ray department, a nurse will escort you and stay with you during the test. A small drip will be placed into a vein in the arm or hand during the procedure. This may be used to give intravenous fluids. It may be necessary to trim some of the hair from the groin area before the test to help skin cleaning.

During the angiogram

The radiologist (x-ray doctor) will inject a local anaesthetic into the skin at the groin "freezing" the area. After this injection the procedure should be fairly painless. The long fine tube (catheter) is then inserted into the artery at the groin (common femoral artery), and using x-rays to help, the radiologist manipulates the catheter into the correct position. You will not feel the catheter being moved around your body. X-ray pictures are taken whilst the dye is injected down the catheter into the blood vessels. To be able to take pictures along a length of arteries, the radiologist will move the bed so that different portions of the arteries can be examined.

Some injections may cause hot flushing for a few seconds, and an occasional feeling of wanting to pass urine. When the test is completed the catheter is removed and pressure will be applied to the groin for approximately ten minutes to minimise any bruising.
You will be taken back to the ward to rest for a few hours. It is important that you lie quietly so that the groin does not bleed again. The nursing staff will check the groin, and foot pulses at regular intervals. If no pulses are present the colour and temperature of the foot is important. Providing all is well, you will be allowed home, but you need someone with transport to take you home, or to accompany you in a taxi. It is important that you rest completely until the next day to ensure that the puncture site in the groin heals up. If after you get home you notice any swelling or bleeding at the puncture site, you should press on this and call your GP's surgery for advice.

The radiologist and vascular surgeon will look at the x-ray pictures and discuss their findings. They will decide the best form of treatment for you and then write to you, or see you again in the outpatient clinic. The treatment can then be discussed and as always it is the patient who decides whether to proceed with treatment or not.
What is an Angioplasty ?
An angioplasty is a procedure where a balloon is passed into your artery on the end of a tube (catheter) and is inflated (blown up) to treat a narrowed or blocked artery. This technique means that surgery may be avoided in many cases. There are two techniques for performing angioplasty - transluminal and subintimal. In the transluminal technique the balloon is placed in the centre of the artery (in the lumen) where blood would normally flow. In subintimal angioplasty the balloon is intentionally placed within the layers of the arterial wall. As far as the patient is concerned, angioplasty is very similar to an angiogram except that a slightly bigger catheter is used and therefore the risks of bleeding are slightly greater. For this reason, in most cases, you will be asked to stay overnight. You will usually be asked to start taking aspirin before you are admitted as this makes the blood less sticky. A common dose is 75 mg per day. If you have a stomach ulcer or are allergic to aspirin, please tell your doctor. The angiogram opposite shows the artery on the left before angioplasty and on the right following angioplasty.





Angioplasty takes a little longer than simple angiography and you may feel the doctor changing, and pushing, catheters in and out of your groin artery. Although this is occasionally a little uncomfortable, it is not usually too painful. Sometimes, it will be necessary to insert a special device called a stent to keep the artery open. This is just a small metal tube that expands in your artery to keep the area open and allow more blood to flow through. Stents appear to be especially useful in larger arteries above the level of the hip joints. They can be used in arteries in the thigh but results are mixed. A recent trial (RESILIENT) compared a newer stent (the LifeStent) against angioplasty alone in the arteries in the thigh. Early results indicate that the stent maintains patency of the artery in the thigh at least for the first 12 months, despite nine stents fracturing. Only longer term published results will tell us whether this translates into longer term clinical benefit.


In some cases Heparin injections (anticoagulation) will be given for 24 hours to prevent the blood clotting at the site of the angioplasty. Rarely you may require warfarin tablets to thin the blood for a few months. You will normally be allowed home the following day. If you are given heparin or warfarin this may delay your departure by a few days. You will be seen again in the clinic by your surgeon to assess the success of the angioplasty and to decide upon any further treatments. Unfortunately, in about 10% of cases, angioplasty is not successful and other treatments will need to be considered. In addition, even where successful angioplasty has been performed, there is a risk that the area in the artery will narrow down again. After one year, about 20-30% of arteries will have re-narrowed. In some cases, it may be possible to repeat the angioplasty at that time although in others this may not be possible. Very rarely, if angioplasty does not work, the circulation may actually worsen. If this is a particular risk in your case, your surgeon and /or radiologist will discuss the risks with you.

Bleeding – a small amount of bleeding sometimes occurs when the catheter is removed. Before the procedure is finished, the radiologist will ensure, by pressing on the artery that all bleeding has completely stopped. Occasionally this bleeding can cause a small lump around the groin and commonly causes some bruising in the skin for a few days after the procedure. This is normal and will clear up on its own. Serious bleeding is very uncommon.

False aneurysm - rarely a pulsating lump develops in the groin at the site where the catheter was inserted into the artery. This is because bleeding took place after the catheter was removed. The clot produced forms a small sac with liquid blood in the centre. This blood pulses because it is connected to the artery through the hole made by the catheter. The sac with blood in the centre is called a false aneurysm. These days this problem can usually be treated by a simple injection into the sac to make the liquid blood in the centre form a clot and block the small hole in the artery.

Pain/Discomfort – local anaesthetic is injected into the skin just before the catheter is placed into the artery. This should take away any severe pain, but it is likely you may feel some gentle pushing and pulling during the procedure. The blood vessels themselves do not feel the guiding wire or catheter. Injecting the dye sometimes causes a sensation of warmth, but this usually lasts only a few seconds. Reactions to the dye – Reactions to modern dyes apart from the sensation of warmth are very uncommon. Various reactions and allergies can still occur and the staffs are fully trained and equipped to deal with any reaction which may occur. Reactions may include skin rashes, vomiting, asthma, low blood pressure and disturbances of heart beat and kidney damage. Damage to blood vessels – this can occur during angioplasty especially if the artery is already badly diseased. The catheter may make a hole in the blood vessel or strip the lining from the blood vessel.

Usually these problems can be dealt with by the radiologist at the time of the procedure. If it is not possible to deal with the problem in radiology then an operation may be required. Nerve effects– sometimes the local anaesthetic can numb main nerves in the front of the thigh, causing numbness going down the leg and weakness. This will wear off after an hour or so. Equipment failure – it is theoretically possible for the catheter or its guiding wire to break and leave a fragment inside the body. Procedures are available to deal with this eventuality in the radiology department but occasionally surgery may be required. Failure of technique – occasionally it is not possible to perform the angioplasty. This may be because the artery is too diseased. Sometimes inserting a metal stent to hold the artery open can be helpful, especially for larger arteries in the pelvis. Blood clots – blood clots can form at the angioplasty site within the artery. These can usually be dealt with by using enzymes that dissolve the lot, but can sometimes be a problem which can cause the circulation to deteriorate.

Kidney damage - Damage can occur to cells in the kidney during an angiogram. This can lead to a deterioration in kidney function if your kidneys are already diseased. The cause of the damage is the special radio-opaque dye that is injected into the arteries so that they can be seen with X-rays. Although other dyes are available (gadolinium) they are probably no safer than conventional dyes. If the doctors know your kidneys may be at risk during an angiogram, they can reduce the risks of damage by giving extra fluids in an intravenous drip before during and after your angiogram.

Can I do anything to help myself?
You cannot do anything to relieve the actual narrowing in your arteries. However, you can improve your general health by taking regular exercise, stopping smoking and reducing the fat in your diet. Your blood pressure should also be measured and kept under control. These actions will help slow down the
hardening of the arteries which caused the problem in the first place, and may avoid the need for further treatment in the future.

How effective is angioplasty?
The effectiveness of angioplasty depends on exactly which type of angioplasty is performed. In general if the artery is only narrowed, and has not totally blocked, then angioplasty is more likely to be successful and any improvement is likely to last longer. If the length of artery to be treated is short (less than 5cms), then angioplasty is likely to be more successful than if a much longer length of artery is diseased and requires treatment. Angioplasty is more likely to be successful in a large artery (iliac arteries in pelvis) versus a small artery (tibial arteries in calf). A 1 cm long narrowing in a large iliac artery (in the pelvis) supplying the leg, treated by angioplasty is likely to produce a very good result. In contrast a 10cms blockage in a tibial artery in the calf may be very tricky to treat by angioplasty.

Overall angioplasty is technically successful in 90-100% of patients, but the late results can be less impressive. For short arterial occlusions in the thigh the angioplasty site can remain open in 60-80% of patients, but the effect on symptoms is frequently poorly investigated. In less suitable arterial disease the benefits of angioplasty may be considerably less. In a study reporting the results of subintimal angioplasty for severe arterial disease in the legs only 25% (25 in 100) of the arteries were still open at 12 months and results were poorer when segments of artery greater than 10cms long were treated (Smith BM et al, 2005).A recent study (BASIL, 2005) has compared angioplasty with bypass surgery in patients with severe limb ischaemia (see bypass surgery).

In patients who are suitable for both angioplasty and bypass surgery, an angioplasty first strategy had broadly similar outcomes to surgery. Unfortunately, the majority of patients presenting with severe disease (approximately 80%) are not suitable for both strategies and are more likely to require surgery. In general vascular specialists will attempt angioplasty first in place of surgery if there is a reasonable chance of a good outcome. If this fails bypass surgery is still likely to be an option. In the USA, since 1996, there has been a 40% increase in the use of angioplasty in the leg arteries and a 30% decline in open bypass surgery (Nowygrod, 2006).

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